从零开始学习docker（八）多台机器通信

撸了今年阿里、头条和美团的面试，我有一个重要发现.......>>>

在上一节中，我们介绍了在同一个机器里面同一个docker里面不同的容器如何进行通信的。这一节我们介绍如何在不同的Linux机器上面的容器通信。

分布式存储有很多工具，今天选择etcd工具，这个是开源的免费分布式存储。

准备实验环境：

docker node1 ip: 192.168.0.109

docker node2 ip: 192.168.0.107

在docker node1 上,下载解压https://github.com/etcd-io/etcd/releases/tag/v3.3.13

vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ nohup ./etcd --name docker-node1 --initial-advertise-peer-urls http://192.168.0.109:2380 \
> --listen-peer-urls http://192.168.0.109:2380 \
> --listen-client-urls http://192.168.0.109:2379,http://127.0.0.1:2379 \
> --advertise-client-urls http://192.168.0.109:2379 \
> --initial-cluster-token etcd-cluster \
> --initial-cluster docker-node1=http://192.168.0.109:2380,docker-node2=http://192.168.0.107:2380 \
> --initial-cluster-state new &
[1] 3870
vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ nohup: ignoring input and appending output to 'nohup.out'

--name 表示这个名字是docker-node1

--initial-advertise-peer-urls 表示本地地址

./etcdctl cluster-health
member 72400c6f5c5691f3 is healthy: got healthy result from http://172.16.247.131:2379
member dc0810ee9a06524d is healthy: got healthy result from http://172.16.247.132:2379
cluster is healthy

在docker node2上也去执行：

wget https://github.com/coreos/etcd/releases/download/v3.0.12/etcd-v3.0.12-linux-amd64.tar.gz
vincent@swarm-worker-1:~/etcd-v3.3.13-linux-amd64$ ./etcd --name docker-node2 --initial-advertise-peer-urls http://192.168.0.107:2380 \
> --listen-peer-urls http://192.168.0.107:2380 \
> --listen-client-urls http://192.168.0.107:2379,http://127.0.0.1:2379 \
> --advertise-client-urls http://192.168.0.107:2379 \
> --initial-cluster-token etcd-cluster \
> --initial-cluster docker-node1=http://192.168.0.109:2380,docker-node2=http://192.168.0.107:2380 \
> --initial-cluster-state new &

如何确定我们的cluster已经成功建立了：

在node1上执行：

vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ ./etcdctl cluster-health
member beb7fd3596aa26eb is healthy: got healthy result from http://192.168.0.109:2379
member e6bdc10e37172e00 is healthy: got healthy result from http://192.168.0.107:2379
cluster is healthy

然后在node2上执行：

vincent@swarm-worker-1:~/etcd-v3.3.13-linux-amd64$ ./etcdctl cluster-health
member beb7fd3596aa26eb is healthy: got healthy result from http://192.168.0.109:2379
member e6bdc10e37172e00 is healthy: got healthy result from http://192.168.0.107:2379
cluster is healthy

这样我们就在两台机器上搭建了一个分布式存储

重启docker服务

因为我们要让docker知道我们要去使用分布式存储。

在docker-node1上执行：

vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ sudo service docker stop
[sudo] password for vincent:
vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ docker --version
Docker version 17.12.0-ce, build c97c6d6

然后手动启动docker：

vincent@swarm-manager:~/etcd-v3.3.13-linux-amd64$ sudo /usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store=etcd://192.168.0.109:2379 --cluster-advertise=192.168.0.109:2375&
[2] 4153

在docker-node2上执行：

sudo service docker stop
sudo /usr/bin/dockerd -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock --cluster-store=etcd://192.168.0.109:2379 --cluster-advertise=192.168.0.109:2375&

创建overlay network

在docker-node1上创建一个demo的overlay network

sudo docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
f6acf1d69b7c        bridge              bridge              local
c051f46f8a15        host                host                local
4caf51fb3438        none                null                local

docker network create -d overlay demo
1607f5636b8515d7e06d2f13261d32d8370c72de99ffb688ccdce3f6d8bce898

docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
f6acf1d69b7c        bridge              bridge              local
1607f5636b85        demo                overlay             global
c051f46f8a15        host                host                local
4caf51fb3438        none                null                local

查看overlay网络的详细信息：

docker network inspect demo
[{"Name": "demo","Id": "1607f5636b8515d7e06d2f13261d32d8370c72de99ffb688ccdce3f6d8bce898","Created": "2019-07-01T07:52:43.137469208-07:00","Scope": "global","Driver": "overlay","EnableIPv6": false,"IPAM": {"Driver": "default","Options": {},"Config": [{"Subnet": "10.0.0.0/24","Gateway": "10.0.0.1"}]},"Internal": false,"Attachable": false,"Ingress": false,"ConfigFrom": {"Network": ""},"ConfigOnly": false,"Containers": {},"Options": {},"Labels": {}}
]

我们会看到在node2上，这个demo的overlay network会被同步创建:

docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
e944ecd3d81f        bridge              bridge              local
1607f5636b85        demo                overlay             global
ca2b5e91ee2f        host                host                local
cfb09007c0ce        none                null                local

创建连接demo网络的容器

在docker-node1上创建容器：

docker run -d --name test1 --network demo vincent/ubuntu-base /bin/bash -c "while true; do sleep 3600; done"
c86061fd856cca0d157cc602cd9b98edd9f0fa4db9a26aa77ae2b054d6d804f1

docker container ls
CONTAINER ID        IMAGE                 COMMAND                  CREATED              STATUS              PORTS               NAMES
c86061fd856c        vincent/ubuntu-base   "/bin/bash -c 'while…"   About a minute ago   Up About a minute

查看test1的ip：

docker exec test1 ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:0a:00:00:02inet addr:10.0.0.2  Bcast:10.0.0.255  Mask:255.255.255.0UP BROADCAST RUNNING MULTICAST  MTU:1450  Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)eth1      Link encap:Ethernet  HWaddr 02:42:ac:12:00:02inet addr:172.18.0.2  Bcast:172.18.255.255  Mask:255.255.0.0UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1RX packets:16 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:1308 (1.3 KB)  TX bytes:0 (0.0 B)lo        Link encap:Local Loopbackinet addr:127.0.0.1  Mask:255.0.0.0UP LOOPBACK RUNNING  MTU:65536  Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

在docker-node2上新建容器test2：

docker run -d --name test2 --network demo vincent/ubuntu-base /bin/bash -c "while true; do sleep 3600; done"
31f87913be02db7a8033b407c559a7a213445384d735239ff6504318c5077e46

在docker-node2上测试连通性

docker exec -it test2 ifconfig
eth0      Link encap:Ethernet  HWaddr 02:42:0a:00:00:03inet addr:10.0.0.3  Bcast:10.0.0.255  Mask:255.255.255.0UP BROADCAST RUNNING MULTICAST  MTU:1450  Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)eth1      Link encap:Ethernet  HWaddr 02:42:ac:12:00:02inet addr:172.18.0.2  Bcast:172.18.255.255  Mask:255.255.0.0UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1RX packets:16 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:0RX bytes:1308 (1.3 KB)  TX bytes:0 (0.0 B)lo        Link encap:Local Loopbackinet addr:127.0.0.1  Mask:255.0.0.0UP LOOPBACK RUNNING  MTU:65536  Metric:1RX packets:0 errors:0 dropped:0 overruns:0 frame:0TX packets:0 errors:0 dropped:0 overruns:0 carrier:0collisions:0 txqueuelen:1RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

这两个container之间可以连通。

https://blog.csdn.net/qq_37880968/article/details/86747883

https://www.imooc.com/article/47152

https://blog.csdn.net/u013641234/article/details/83964251